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48-574: Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland , New Zealand. The 5.5 km (3.4 mi) wide island is a symmetrical shield volcano cone capped by central scoria cones, reaching a height of 260 m (850 ft). Rangitoto is the youngest and largest of the approximately 50 volcanoes of the Auckland volcanic field , having erupted in two phases about 1450 CE and 1500 CE and covering an area of 2,311 ha (5,710 acres). It

96-500: A 150 m (490 ft) deep hole was drilled through the western flank of Rangitoto in February 2014. No supporting evidence for these hypothesised small eruptions up to 1000 yrs before the main eruption of Rangitoto was found. The University scientists did, however, core a thin basalt lava flow within marine sediment dated at 6000 years old, and hypothesised that this was an even earlier eruption from Rangitoto. Civil Defence officials said

144-640: A significant effect on bird species diversity and abundance, due to the presence of other predators. Stoats , rabbits , mice , rats , cats and hedgehogs remained a problem on the island, but the Department of Conservation (DOC) aimed to eradicate them beginning with the poisoning of black rats , brown rats and mice and in August 2011, both Rangitoto and neighbouring Motutapu Islands were officially declared pest-free with both islands now also boasting populations of newly translocated North Island saddlebacks . As

192-406: A smaller and much older and unrelated volcano, a view possibly supported, but certainly not proven, by recent microfossil research from the marine sediments obtained from beneath Rangitoto in the stratigraphic drillhole. The southern cone of Rangitoto Volcano with its own crater likely buries a more northern explosion crater and tuff ring formed during the early wet phase of eruption in the middle of

240-594: A wrecking ground for unwanted ships, and the remains of several wrecks are still visible at low tide. At least 13 ships were wrecked from 1887, the last being the former Wellington and, later, Waiheke ferry, Duchess, in June 1947. (built 1897 - iron deck framing remained in 2014). Other ships include Ngapuhi (1900 - her stern remained in 2014), Jubilee (1857), Arapawa (1908), Rothesay Bay (1877), Gladbrook (ex Countess of Anglesea 1877), Elinor Vernon (1876), Polly (ex Skovland 1891), Columbia (1899 - part of

288-412: Is a hard-burnt yellow clinker brick. Greppin clinkers were mainly used for facing railway structures at the end of the 19th and in the early 20th centuries. These reclaimed brick tiles are not sliced from full clinker bricks but from half clinkers. Full clinkers are very hard and if used as flooring would not only rip one’s feet apart but also one’s shoes. The surface of a Klinker brick is so hard that it

336-446: Is almost glass like and any rough edges wouldn’t soften. Half Klinker bricks have been fired at high temperatures in wood fired kilns over 100 years ago but because they have been sun dried prior to being loaded in the kiln, there has not been the same intensity of vitrification as with a full clinker brick. This makes them softer underfoot and therefore far more desirable for use in flooring. They also wear and soften with age. Because

384-589: Is camping at Home Bay on the adjacent Motutapu Island. 36°47′12″S 174°51′36″E  /  36.786742°S 174.860115°E  / -36.786742; 174.860115 Volcanic island There are a number of volcanic islands that rise no more than 1 metre (3 ft 3 in) above sea level , often classified as islets or rocks, while some low islands, such as Banaba , Henderson Island , Makatea , Nauru , and Niue , rise over 50 metres (160 ft) above sea level. The two types of islands are often found in proximity to each other, especially among

432-487: Is distinctly offset by about 3.5 km (2.2 mi) from the Rangitoto vents to the east of the fault and that there is a density beneath the southern cones. This along with magnetic studies has been interpreted to show a solidified intra-cone feeder dyke as the most likely explanation for the mass under the southern cone system and some buried mass to the north of the northern cone whose character can not be fully modelled but

480-485: Is likely to be a feeder dyke. At depth of more than 6 km (3.7 mi) the magma may have initially tracked the Islington Bay Fault in this modelling. Withdrawal of magma back down the throat of the volcano at the end of the eruptions has resulted in slight subsidence of the scoria cones. This has created a moat-like ring around the central scoria cones, which the main track to Rangitoto's summit passes through on

528-604: Is linked to a traditional story of a fight between Tama-te-kapua , captain of the Arawa canoe, and Hoturoa , captain of the Tainui canoe. The name Ngā Rangi-i-totongia-a Tama-te-kapua ("The days of the bleeding of Tama-te-kapua") refers to how Tama-te-kapua was injured in the fight. The peaks of the island were known by the names Ngā Pona Toru o Peretū ("The Three Knuckles of Peretū") or Ngā Tuaitara o Taikehu ("The Dorsal Fins of Taikehu"). Ngā Pona Toru o Peretū, often shortened to Peretū

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576-437: Is possible to cope varied shaped elements (e.g., clinker expressionism, see picture). Earlier clinkers were often used in civil engineering works, for example in bridge building, the construction of sewers and hydraulic structures, for mortar floodgates and hoppers or as paving stones for road construction. The German sculptor Ernst Barlach worked with clinkers, which were produced according to his specifications, for example by

624-463: Is separated from the mainland of Auckland's North Shore by the Rangitoto Channel . Since World War II , it has been linked by a causeway to the much older, non-volcanic Motutapu Island . Rangitoto is Māori for 'Bloody Sky', with the name coming from the full phrase Ngā Rangi-i-totongia-a Tama-te-kapua ("The days of the bleeding of Tama-te-kapua"). Tama-te-kapua was the captain of

672-474: Is similar to the situation seen on the coast at Queen Victoria Rock, near the Rangitoto Lighthouse , where lava flows have ploughed into the soft seafloor sediment and intruded into it, bringing at least one sediment slab up to high tide level. Thus no evidence has been found so far to support the hypotheses of earlier eruptions of Rangitoto between 620 and 8000 yrs ago. It is possible that Rangitoto buried

720-541: Is sometimes spelled "klinker" which is the contemporary Dutch word for the brick. Both terms are onomatopoeic , derived from the Middle Dutch klinkaerd , later klinker , from klinken (“to ring, resound”). Clinker bricks are also known as Dutch paving bricks. In 18th century New York , the Dutch interspersed dark clinkers with regular bricks. Some used clinkers to spell out their family initials on brick dwellings such as

768-510: Is the traditional Ngāi Tai ki Tāmaki name for the three peaks of the island, and was a name given by Taikehu, a captain of the Tainui canoe. Rangitoto is associated with many traditional stories and myths. One involves Tiriwa (the namesake of the traditil name for the Waitākere Ranges , Te Wao Nui o Tiriwa), a chief of the supernatural Tūrehu people, who uplifted Rangitoto from Karekare on

816-525: The Arawa waka (canoe) and was badly wounded on the island, after having lost a battle with the Tainui iwi (tribe) at Islington Bay. Rangitoto formed during two phases of eruptions that may have lasted only 5–10 years, about 600 years ago. The first part of the eruption sequence, dated by radiocarbon methods at about 627 years ago (= 553 ± 7 yrs BP) was initially wet and produced surges of volcanic ash that mantled neighbouring Motutapu Island from alkaline olivine basalt eruptives sourced from

864-827: The Arts and Crafts movement . In the United States , clinker bricks were popularized by the Pasadena, California architecture firm Greene and Greene , who used them for walls, foundations, and chimneys. On the East Coast, clinkers were used extensively in the Colonial Revival style of architecture. Modern brick-making techniques do not produce clinker bricks, and they have become rare. Builders can procure clinkers from salvage companies; alternatively, some brickmakers purposefully manufacture clinker bricks or produce imitations. Clinker

912-476: The German Institute for Standardization 's DIN 105. They differ between full clinker (KMz) with a density of 2.0 to 2.2 kg/dm (120 to 140 lb/cu ft) and high hole clinker (KHLz) with a density of 1.6 to 1.8 kg/dm (100 to 112 lb/cu ft). Because of their low porosity, clinker bricks are inferior thermal insulators, compared to normal bricks. Canal clinkers are named according to

960-519: The Jan Van Hoesen House . Clinkers consist of bits and ends, field-late and white-burning or red-burning clays. Through different mixtures of the raw ingredients, many varied color nuances can be achieved. For the production of masonry units the source materials—clay and water—are mixed and formed industrially in a string extrusion process. For special purposes, for example the restoration of listed buildings, hand-formed clinkers are used. During

1008-676: The construction of buildings . Clinker bricks are produced when wet clay bricks are exposed to excessive heat during the firing process , sintering the surface of the brick and forming a shiny, dark-colored coating.   Clinker bricks have a blackened appearance, and they are often misshapen or split. Clinkers are so named for the metallic sound they make when struck together. Clinker bricks are denser, heavier, and more irregular than standard bricks. Clinkers are water-resistant and durable, but have higher thermal conductivity than more porous red bricks, lending less insulation to climate-controlled structures. The brick-firing kilns of

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1056-555: The islands of the South Pacific Ocean , where low islands are found on the fringing reefs that surround most volcanic islands. Volcanic islands normally rise above a hotspot or subduction zone . Volcanic islands usually range in size between 1 and 104 square kilometres (0.4 and 40 sq mi). Islands above a certain size usually have fresh groundwater , while low islands often do not, so volcanic islands are more likely to be habitable. Many volcanic islands emerge from

1104-585: The German Institute for Standardization’s DIN 4051. Clinkers are frost resisting and, thus are suited particularly for facades. The formats of the clinker stones are named according to the German Institute for Standardization’s DIN 1053. Base for the different formats is the normal format (NF) with length 240 millimetres (9.4 in), width 115 millimetres (4.5 in) and height 71 millimetres (2.8 in). For facade layouts architects also order clinkers produced in special dimensions. For use in facades , it

1152-402: The Rangitoto drillcore has exactly the same chemistry as the lowest/oldest flows of the cored shield volcano above and has recently been shown to also have the same U-Th-Ra signature and both must have been erupted and solidified at virtually the same time. The thin "flow" is therefore likely to be basalt lava that was intruded into the sediment as the shield volcano was starting to be formed. This

1200-507: The Waitemata Harbour. The external form of Rangitoto consists of a circular, gently sloping shield composed of numerous overlapping lava flows. The centre of the volcano is capped by the remains of much steeper scoria cones made of loose scoria that was erupted by dry-style fire-fountaining from several vents. Gravitational studies show a relationship with the Islington Bay Fault which strikes between Rangitoto and Mototapu islands but which

1248-565: The area is a DOC-administered reserve (in partnership with the tangata whenua Ngāi Tai and Ngāti Paoa ), visitors may not take dogs or other animals onto the islands. The volcano erupted within the historical memory of the local Māori iwi (tribes). Human footprints have been found between layers of Rangitoto volcanic ash on the adjoining Motutapu Island . Ngāi Tai was the iwi living on Motutapu, and considers both islands their ancestral home. Ngāti Paoa also has links with Rangitoto. The name Rangitoto literally means "red sky", and

1296-595: The ban and because the island has become a scenic reserve. However, 30 of the 140 baches remain as of 2010, and some are being preserved to show how the island used to be, once boasting a permanent community of several hundred people, including many children. The buildings included some more permanent structures like a seawater pool built of quarried stones by convict labour, located close to the current ferry quay. Regular ferry services and island tours by tractor-trailer are provided by Fullers from Auckland city centre . A boardwalk with around 300 steps allows visitors to reach

1344-630: The brickyard of Ilse Bergbau AG. Clinker bricks take on a special coloring, often greenish tones, if burnt with peat. The Chilehaus and the Ramada Hotel in Hamburg are famous buildings built with peat-fired clinker. The last ring stove for peat-fired clinker still operating is in Nenndorf near Aurich (East Frisia), producing bricks marketed under the name “Wittmunder Torfbrandklinker” (peat-fired clinker of Wittmund ). Greppiner Klinker (clinker of Greppin)

1392-413: The caves are signposted. Lava tubes are formed when low-viscosity molten lava known as pahoehoe flows and cools on the outside due to contact with the ground and air, to form a hard crust allowing the still-liquid molten lava to continue to flow through inside. In several places the lava tube roof has collapsed thus providing several different entrances to the one elongate tube. A torch is needed to explore

1440-430: The caves. The longest known cave is about 120 m long. Because there are virtually no streams on the island, plants rely on rainfall for moisture. It has the largest forest of pohutukawa trees in the world, as well as many northern rātā trees. In total, more than 200 species of trees and flowers thrive on the island, including several species of orchid , as well as more than 40 types of ferns . The vegetation pattern

1488-443: The deep abyss of the ocean, and feature rough or mountainous landscapes in their interiors and a diverse array of summit elevations. Researchers have observed that the island will often be covered by dense tropical forest. These limit settlement on the interior of many islands, forcing communities to develop along the coast. Larger islands may have rivers, resulting in flood hazards. Rivers deliver sediment downstream, which can dominate

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1536-544: The discovery did not make living in Auckland any more dangerous, but did change their view of how an eruption might proceed. These headline-grabbing results were controversial and not accepted by all geologists. In 2018 many of the original group of Auckland University geologists reported on their latest research and reinterpretation of the evidence and concluded that Rangitoto only erupted once, about 600 yrs ago, possibly in two phases. The thin lava flow within 6000 yr-old sediment in

1584-400: The drying process, the water concentration decreases to approximately 3%. Then clinkers are fired at temperatures between 1,100 and 1,300 °C (2,010 and 2,370 °F) in a tunnel kiln (earlier in ring kilns), in contrast to the 800 to 1,200 °C (1,470 to 2,190 °F) temperature range seen with normal bricks. In Germany, clinker bricks (German: Klinkerziegel ) are named according to

1632-455: The early 20th century—called brick clamps or "beehive" kilns—did not heat evenly, and the bricks that were too close to the fire emerged harder, darker, and with more vibrant colors, according to the minerals present in the clay. Initially, these clinkers were discarded as defective, but around 1900, the bricks were salvaged by architects who found them to be usable, distinctive, and charming. Clinker bricks were widely admired by adherents of

1680-408: The gulf. The bay is used by Auckland boat-owners as a refuge, as it is quite sheltered from the prevailing southwest winds. Military installations were built during World War II to support the Auckland harbour defences and to house U.S. troops or store mines . The most visited remains of these installations is the old observation post on the summit. The northern shore of the island was used as

1728-521: The importance of implementing effective risk mitigation plans that include nature-based solutions to improve societal safety on these islands. These involve leveraging natural processes and ecosystems to reduce hazard impacts. This can include the restoration of natural barriers like mangroves or coral reefs that protect against tsunamis and storm surges or the maintenance of natural water catchments that can mitigate flood risks. Clinker brick Clinker bricks are partially- vitrified bricks used in

1776-450: The keel and frame remained in 2014), Dartford (1877) and Rarawa (1903 - the bow, framing, iron plating and stern with two propeller shaft housings were visible above the low water mark in 2014). Baches (small holiday houses) were built around the island's edge in the 1920s and 1930s. The legality of their existence was doubtful from the start and the building of further baches was banned in 1937. Most have since been removed because of

1824-464: The mid 19th century and survived until the 1880s. Fallow deer were introduced to Motutapu in 1862 and spread to Rangitoto, but disappeared by the 1980s. The brush-tailed rock-wallaby was introduced to Motutapu in 1873, and was common on Rangitoto by 1912, and the brushtail possum was introduced in 1931 and again in 1946. Both were eradicated in a campaign from 1990 to 1996 using 1080 and cyanide poison and dogs. The eradication campaign did not have

1872-415: The north cone area. The later part of the eruption dated at about 578 years ago (= 504 ± 5 yrs BP) was dry and built most of Rangitoto, erupting all the sub-alkaline basaltic lava flows of the shield and the southern scoria cone at the apex that mostly buried the north cone. The 2.3 km (0.55 cu mi) of material that erupted from the volcano was nearly as much as the combined mass produced by all

1920-525: The previous eruptions in the Auckland volcanic field, which were spread over nearly 200,000 years. In 2013, scientists from Auckland University reported that Rangitoto had been much more active in the past than previously thought, suggesting it had been active on and off for around 1000 years before the final eruptions around 600 years ago. This was based on recognition of a number of horizons of tiny volcanic glass shards, seemingly erupted from Rangitoto, in sediment cores from Lake Pupuke. To test this hypothesis,

1968-454: The process of transforming the island into a more habitable area for most plants (an example of primary succession ), which is one of the reasons why the local forests are relatively young and do not yet support a large bird population. However, the Kākā , a New Zealand-endemic parrot , is thought to have lived on the island in pre-European times. Goats were present on Rangitoto in large numbers in

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2016-473: The shape of the coast and contribute to erosion. Tall volcanic islands are often surrounded by protective fringing or barrier reefs, creating lagoons. The unique geological and geographical characteristics of volcanic islands make them prone to many natural hazards, which are expected to worsen due to climate change . These include volcanic eruptions, earthquakes, tsunamis, landslides, and severe weather events like hurricanes or typhoons. Studies have highlighted

2064-399: The summit and enjoy a view of the wooded crater. The distance to the summit is 2.4 km (1.5 mi), a one–hour walk by the most direct route. An alternative to walking, a land train, coordinated with the ferry sailings, takes visitors to a short way below the summit. Sea kayak trips from the mainland to the island are also available. There are no campsites on the island, though there

2112-454: The summit to Islington Bay by 1900. For over 30 years (from 1898 to 1930), scoria was quarried from near the shoreline on the west side of Islington Bay as building material for Auckland. From 1925 to 1936, prison labour built roads on the island and a track to the summit. Islington Bay was formed in the southeast area of the island. Formerly known as Drunks Bay, it was used as a drying out area for inebriated crews before they ventured out of

2160-635: The tears of the tupua for their former home. The island was purchased for £15 by the Crown in 1854, very early in New Zealand's colonisation by Europeans, and for many years served as a source of basalt for the local construction industry. It was set aside as a recreation reserve in 1890, and became a favourite spot for daytrippers. Some development occurred nonetheless. In 1892, salt works were created on 5 acres (20,000 m) near Mackenzies Bay. The wharf and summit road were opened in 1897, with another road linking

2208-436: The way to the summit and gives a distinctive shape to the island. In some parts of the island, fields of clinker -like black basalt lava are exposed where vegetation has yet to colonise the surface of the youngest lava flows. About 200 metres from the top of the mountain on the eastern side visitors can walk through sections of two lava tubes — cave-like tubes left behind after the passage of liquid lava. The more accessible of

2256-559: The west coast, as a show of his strength. Others involve a ' tupua ' couple, children of the Fire Gods. After quarreling and cursing Mahuika , the fire-goddess, they lost their home on the mainland because it was destroyed by Mataoho , god of earthquakes and eruptions, on Mahuika's behalf. Lake Pupuke on the North Shore was created in the destruction, while Rangitoto rose from the sea. The mists surrounding Rangitoto at certain times are called

2304-408: Was influenced by the more recent eruptions creating lava flow crevices where pōhutukawa trees ( Metrosideros ssp.) grow. The island is considered especially significant because all stages from raw lava fields to scrub establishment and sparse forests are visible. As lava fields contain no soil of the typical kind, windblown matter and slow breaking-down processes of the native flora are still in

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